[grid] Reworking CLI commands to avoid direct use of System.out and S…

…ystem.err

It is possible now to use custom streams for output. This allows to 1) redirect output programmatically, 2) write test that check output

java/server/src/org/openqa/selenium/cli/CliCommand.java

@@ -17,13 +17,15 @@
 
 package org.openqa.selenium.cli;
 
+import java.io.PrintStream;
+
 public interface CliCommand {
 
   String getName();
 
   String getDescription();
 
-  Executable configure(String... args);
+  Executable configure(PrintStream out, PrintStream err, String... args);
 
   default boolean isShown() {
     return true;

java/server/src/org/openqa/selenium/grid/Main.java

@@ -21,6 +21,7 @@
 import org.openqa.selenium.cli.WrappedPrintWriter;
 
 import java.io.File;
+import java.io.PrintStream;
 import java.io.PrintWriter;
 import java.io.UncheckedIOException;
 import java.net.MalformedURLException;
@@ -44,9 +45,25 @@ public class Main {
 
   private static final Logger LOG = Logger.getLogger(Main.class.getName());
 
+  private final PrintStream out;
+  private final PrintStream err;
+  private final String[] args;
+
   public static void main(String[] args) throws Exception {
+    new Main(System.out, System.err, args).go();
+  }
+
+  Main(PrintStream out, PrintStream err, String[] args) {
+    // It's not private to make it visible for tests
+    this.out = out;
+    this.err = err;
+    this.args = args;
+  }
+
+  void go() throws Exception {
+    // It's not private to make it visible for tests
     if (args.length == 0) {
-      new Help(loadCommands(Main.class.getClassLoader())).configure().run();
+      new Help(loadCommands(Main.class.getClassLoader())).configure(out, err).run();
     } else {
       if ("--ext".equals(args[0])) {
         if (args.length > 1) {
@@ -90,10 +107,10 @@ public static void main(String[] args) throws Exception {
             System.arraycopy(args, 2, remainingArgs, 0, args.length - 2);
             launch(remainingArgs, loader);
           } else {
-            new Help(loadCommands(loader)).configure().run();
+            new Help(loadCommands(loader)).configure(out, err).run();
           }
         } else {
-          new Help(loadCommands(Main.class.getClassLoader())).configure().run();
+          new Help(loadCommands(Main.class.getClassLoader())).configure(out, err).run();
         }
 
       } else {
@@ -108,7 +125,7 @@ private static Set<CliCommand> loadCommands(ClassLoader loader) {
     return commands;
   }
 
-  private static void launch(String[] args, ClassLoader loader) throws Exception {
+  private void launch(String[] args, ClassLoader loader) throws Exception {
     String commandName = args[0];
     String[] remainingArgs = new String[args.length - 1];
     System.arraycopy(args, 1, remainingArgs, 0, args.length - 1);
@@ -120,7 +137,7 @@ private static void launch(String[] args, ClassLoader loader) throws Exception {
         .findFirst()
         .orElse(new Help(commands));
 
-    command.configure(remainingArgs).run();
+    command.configure(out, err, remainingArgs).run();
   }
 
   private static class Help implements CliCommand {
@@ -143,7 +160,7 @@ public String getDescription() {
     }
 
     @Override
-    public Executable configure(String... args) {
+    public Executable configure(PrintStream out, PrintStream err, String... args) {
       return () -> {
         int longest = commands.stream()
                           .filter(CliCommand::isShown)
@@ -152,28 +169,28 @@ public Executable configure(String... args) {
                           .map(String::length)
                           .orElse(0) + 2;  // two space padding either side
 
-        PrintWriter out = new WrappedPrintWriter(System.out, 72, 0);
-        out.append(getName()).append("\n\n");
-        out.append(getDescription()).append("\n").append("\n");
+        PrintWriter outWriter = new WrappedPrintWriter(out, 72, 0);
+        outWriter.append(getName()).append("\n\n");
+        outWriter.append(getDescription()).append("\n").append("\n");
 
         int indent = Math.min(longest + 2, 25);
         String format = "  %-" + longest + "s";
 
-        PrintWriter indented = new WrappedPrintWriter(System.out, 72, indent);
+        PrintWriter indented = new WrappedPrintWriter(out, 72, indent);
         commands.stream()
           .filter(CliCommand::isShown)
           .forEach(cmd -> indented.format(format, cmd.getName())
             .append(cmd.getDescription())
             .append("\n"));
 
-        out.write("\nFor each command, run with `--help` for command-specific help\n");
-        out.write("\nUse the `--ext` flag before the command name to specify an additional " +
+        outWriter.write("\nFor each command, run with `--help` for command-specific help\n");
+        outWriter.write("\nUse the `--ext` flag before the command name to specify an additional " +
                   "classpath to use with the server (for example, to provide additional " +
                   "commands, or to provide additional driver implementations). For example:\n");
-        out.write(String.format(
+        outWriter.write(String.format(
             "\n  java -jar selenium.jar --ext example.jar%sdir standalone --port 1234",
             File.pathSeparator));
-        System.out.println("\n");
+        out.println("\n");
       };
     }
   }

java/server/src/org/openqa/selenium/grid/TemplateGridCommand.java

@@ -29,13 +29,14 @@
 import org.openqa.selenium.grid.log.LoggingOptions;
 import org.openqa.selenium.grid.server.HelpFlags;
 
+import java.io.PrintStream;
 import java.util.LinkedHashSet;
 import java.util.Set;
 
 public abstract class TemplateGridCommand implements CliCommand {
 
   @Override
-  public final Executable configure(String... args) {
+  public final Executable configure(PrintStream out, PrintStream err, String... args) {
     Set<Object> allFlags = getFlagObjects();
 
     HelpFlags helpFlags = new HelpFlags();
@@ -52,12 +53,12 @@ public final Executable configure(String... args) {
       try {
         commander.parse(args);
       } catch (ParameterException e) {
-        System.err.println(e.getMessage());
+        err.println(e.getMessage());
         commander.usage();
         return;
       }
 
-      if (helpFlags.displayHelp(commander, System.out)) {
+      if (helpFlags.displayHelp(commander, out)) {
         return;
       }
 
@@ -70,7 +71,7 @@ public final Executable configure(String... args) {
 
       Config config = new CompoundConfig(allConfigs.toArray(new Config[0]));
 
-      if (helpFlags.dumpConfig(config, System.out)) {
+      if (helpFlags.dumpConfig(config, out)) {
         return;
       }
 

java/server/src/org/openqa/selenium/grid/commands/InfoCommand.java

@@ -24,6 +24,7 @@
 
 import java.io.BufferedReader;
 import java.io.IOException;
+import java.io.PrintStream;
 import java.io.StringReader;
 import java.nio.charset.StandardCharsets;
 import org.openqa.selenium.cli.CliCommand;
@@ -33,7 +34,6 @@
 import java.io.PrintWriter;
 import java.util.Collections;
 
-
 @AutoService(CliCommand.class)
 public class InfoCommand implements CliCommand {
 
@@ -45,7 +45,7 @@ public String getDescription() {
     return "Prints information for commands and topics.";
   }
 
-  public Executable configure(String... args) {
+  public Executable configure(PrintStream out, PrintStream err, String... args) {
     HelpFlags help = new HelpFlags();
     InfoFlags topic = new InfoFlags();
 
@@ -59,12 +59,12 @@ public Executable configure(String... args) {
       try {
         commander.parse(args);
       } catch (ParameterException e) {
-        System.err.println(e.getMessage());
+        err.println(e.getMessage());
         commander.usage();
         return;
       }
 
-      if (help.displayHelp(commander, System.out)) {
+      if (help.displayHelp(commander, out)) {
         return;
       }
 
@@ -92,11 +92,11 @@ public Executable configure(String... args) {
       String path = getClass().getPackage().getName().replaceAll("\\.", "/") + "/" + toDisplay;
       String content = readContent(path);
 
-      PrintWriter out = new WrappedPrintWriter(System.out, 72, 0);
+      PrintWriter outWriter = new WrappedPrintWriter(out, 72, 0);
 
-      out.printf("\n%s\n%s\n\n", title, String.join("", Collections.nCopies(title.length(), "=")));
-      out.print(content);
-      out.println("\n\n");
+      outWriter.printf("\n%s\n%s\n\n", title, String.join("", Collections.nCopies(title.length(), "=")));
+      outWriter.print(content);
+      outWriter.println("\n\n");
     };
   }
 

java/server/src/org/openqa/selenium/grid/distributor/httpd/DistributorServer.java

@@ -43,7 +43,6 @@
 import java.util.Set;
 import java.util.logging.Logger;
 
-
 @AutoService(CliCommand.class)
 public class DistributorServer extends TemplateGridCommand {